Process for the ammoxidation of propylene

ABSTRACT

This invention provides a new catalyst and process for the oxidation and ammoxidation of olefins. The catalysts are of the formula: TeTin Mop Pq Xm Or WHEREIN X is an element selected from groups IB, IIB, IIIA, IIIB, IVB, VIIB and VIII of the Periodic Table of Elements.

United States Patent 1 Fattore et a1.

1 1 PROCESS FOR THE AMMOXIDATION OF PROPYLENE [75] Inventors: Vittorio Faltore; Bruno Notari, both of San Donato Milanese, 1tu1y [73] Assignee: Smim Progetti S.p.A.. Sun Donato Mil' mese huly 1221 Filed: Feb. 28, 1973 211 AppLNoi1336 703 130} Foreign Application Priority Data Mar l 1972 Italy 21248/72 [52] U.S. Cl .4 260/465.3; 252/439; 260/604 R; 260/680 E [511 Int. Cl." C07C 120/14 [581 Field of Seareh 260/4653; 252/439 1 Aug. 26, 1975 [56] References Cited UNITED STATES PATENTS 1347399 10/1967 Caporali et a1. H 260/465.3 1392189 7/1968 Eden 260/4653 3.641 |02 2/1972 Reulet ct al. 260/46S.3

Primary Examiner-Joseph P. Brust Armrney, Agen! or Firm-Ralph M. Watson 7 Claims, No Drawings PROCESS FOR THE AMMOXIDATION OF PROPYLENF.

The present invention relates to new catalysts for the ammoxidation and oxidation of olcfinic hydrocarbons. to their preparation and to their use for the synthesis of unsaturated nitriles, unsaturated aldehydcs and conjugate dienes starting from olefines.

From the art catalysts are known for the oxidation and ammoxidation of olefines', the most important among them are the ones comprising oxygen containing compounds formed by at least two elements among which Mo-Bi, Sb-U, Sb-Sn, Sb-Fe.

It is moreover known from US. Pat. No. 3,l64,627 that tellurium in oxidized form has been proposed for the production of unsaturated nitriles by reacting olefines, oxygen or a gas containing oxygen and ammonia.

US. Pat. No. 3,164,626 discloses also the use of tellurium in mixture with oxides of other metals as catalyst for the ammoxidation reaction. Not always these catalysts give satisfying conversion, selectivity and productivity values as regards the desired product and this involves, besides, expensive processes for the separation and removal of the by-products.

it has now been found, and this is a first object of the invention, a catalyst capable to carry out the synthesis of unsaturated nitriles, particularly acrylonitrile with high selectivity and conversion.

A second object of the invention is a process for the preparation of the catalysts having the above defined properties.

A third object of the invention is the use of the above mentioned catalyst in the ammoxidation of olefines in order to obtain unsaturated nitriles.

A fourth object of the invention is the use of the same catalyst in the partial oxidation of olefines in order to obtain unsaturated aldehydes.

A fifth object of the invention is the use of the same catalyst in the oxidative dehydrogenation of olefmes in order to obtain conjugate dienes.

All these and other objects are realized according to the present invention which furnishes a catalyst comprising essentially tellurium, titanium and molybdenum, which catalyst can be schematically represented by the following formula TeTi,,Mo,,P,,X,,,O wherein X is an element selected among those belonging to the following groups of the periodic system: lB, 118, "IA, [118, IVB, VIIB and Vlll. Particularly preferred are silver, zinc, cadmium, aluminium, cerium, lanthanum, zirconium, manganese, iron, cobalt and nickel In the aforesaid formula the indices are comprised within the following ranges:

m bctv. con and 0.3 n between I and 1 between 0.05 and 0 4 q bctv-ccn 0 and 0.3

while r represents the value necessary for satisfying the valence with which the different elements are present in the formula.

The X-rays analysis reveals that the catalyst results to be formed by complex oxygen containing compounds of the elements which are part of the composition. There is no evidence of the existence of free molybdates, molybdenum oxides and tellurium oxides The catalyst of the present invention can be prepared starting from usually available raw materials.

As raw materials for introducing tellurium, an advantageous use is made of telluric acid, tellurium oxide. metallic tellurium.

According to the selected compound it will be sufficient either to dissolve the same in water (this is the case of telluric acid) or to treat the same with mineral acids, for instance nitric acid, and/or oxidizing agents, for instance hydrogen peroxide, as in the case of tellurium dioxide or metallic tellurium.

As raw material containing titanium use is made of titanium dioxide in the form of rutile or anatase, trichloride and tetrachloride.

The chlorides are transformed into oxides by precipitation with ammonia. Molybdenum is used in the preferred forms of ammonium molybdate or paramolybdate. which are soluble in water.

As to phosphorus use is made of concentrated solutions of phosphoric acid while as to the other elements which may belong to the catalyst, use is made of soluble salts of same as nitrates, acetates, carbonates and bicarbonatcs.

The preparation procedure depends on the selected type of raw materials and anyhow comprises a series of operations well know to the skilled in the art as precipitation, ctr-precipitation, filtration, drying, atomization, calcination, extrusion and tabletting.

The preferred procedure of the operation comprises dissolving in water telluric acid, possibly adding phosphoric acid, preparing an ammonium paramolybdate solution, mixing the two solutions together and with titanium dioxide in powder, drying by heating at to [00C under stirring, extruding or tabletting after addition of a lubricant and possibly of a product (for instance ammonium bicarbonate) capable of giving the desired porosity.

Alternatively the suspension formed by titanium di oxide and by the dissolved compounds of tellurium, molybdenum and phosphorous can be atomized in order to obtain the catalyst in the form suitable to be used in fluid bed.

In all cases the catalyst is activated by calcination in air at a temperature in the range of from 450 to 550C for a time ranging from V2 an hour to 20 hours and preferably at a temperature ranging from 480C to 530C and for a time ranging from I hour to 4 hours.

The so obtained catalyst is used for producing nitriles. oxygen containing derivatives, conjugated dienes by operating in fixed or fluid bed according to processes which make use of an olefine, oxygen or a gas containing oxygen and, in the case of nitriles, also of ammonia at a temperature ranging from 350C to 550C, preferably from 400C to 500C. The process of the invention is particularly useful when the starting ol efinic compound is selected between propylene and isobutylene at a more or less high purity grade,

Oxygen is generally introduced as air, for exploiting the advantage of the presence of nitrogen for removing the heat produced in the oxidation reaction.

The molar ratio between the olefine and air in the reaction is in the range of from l:5 to l: l5 and preferably from l:l0 to I213.

Ammonia, when provided, is fed at a molar ratio with respect to the olefine in the range of from l.5:l to

Generally the ammoxidation and oxidation reactions are carried out in presence of steam.

The molar ratio with respect to the olefinc, according to which steam is fed, is in the range of from :1 to 2:l. depending on the reaction conditions and on the particular considered reaction.

The pressure at which the reactions are carried out ranges from l to 5 atmospheres, while the space veloc ity of the fed olefine is in the range of from l0 to 500 h"', preferably from 50 to 200 Ii wherein for space velocity we mean the volumes of olefine sent to the reactor per volume of catalyst and per hour, said volumes being calculated at room temperature and atmospheric pressure. The invention will now be more clearly and in detail illustrated by the following examples.

lt is, anyhow, obvious that many modifications can be effected by the man skilled in the art to the mentioned processes without leaving the ambit and the spirit of the invention.

In the examples the terms conversion and selectivity must he understood as follows:

moles of olefine entering the reactormolcs ol' olcl'lnc leaving the reactor conversion .100

moles of olclinc entering the reactor selectivity EXAMPLE l 57 grams of telluric acid (H.;TeO,;) were dissolved in 200 cc of water and 4 grams of phosphoric acid in a solution at 85% were added thereto. Separately 4.4 grams of ammonium paramolybdate were dissolved in cc of water.

The two solutions were joined and to the same 80 grams of titanium dioxide were added.

The whole was dried by heating and under discontinuous stirring.

The mass was activated by calcination at 520C in air for 3 hours in a muffle.

The mass was ground and the fraction having a granulometry in the range of from to mesh ASTM was utilized.

6 cc of catalyst were put in a microreactor heated by an electric oven. The possibility was foreseen of with drawing samples of the gases entering and leaving the reactor in order to analyze same by a chromatography device.

By feeding propylene. air, ammonia and water at the molar ratios of l/l2/1.3/l0 with the propylene space velocities and the temperatures herein below reported. we obtained the following results;

()5 42 grams of telluric acid lH TeOld were weighed and The two solutions were joined and g of titanium dioxide were added thereto. The whole was dried by heating under continuous, slow stirring. The mass was calcined in a mui'ilc at 500C for 5 hours in a stream of air. The mass was then ground and, by sieving, the fraction having a granulometry in the range of from 45 to 150 mesh ASTM was separated.

o cc of catalyst were put in a microreactor and propylene. ammonia, air and water at the molar ratios of IQLJHZHO were fed to the same, the test conditions being the ones referred to in the table wherein there are reported also the obtained results.

and dissolved in cc of water. 32 g of metallic tellurium were added, said tellurium being maintained in suspension by strong stirring. The whole was heated at 60C and 200 cc of volumes hydrogen peroxide were slowly added, letting the temperature be always lower than 95C.

At last a solution was obtained to which 4 grams of phosphoric acid at 85% were added.

The solution was mixed with 80 g of titanium dioxide and dried by heating under an intermittent stirring.

The catalyst was calcined at 530C for 3 hours in a muffle in a stream of air.

6 cc of catalyst having a granulometry in the range of from 45 to mesh ASTM were put in a microreactor to which propylene, ammonia, air and water were fed at molar ratios of l/l.3/ll.S/l0. The test conditions and the results are reported in the following table.

280 grams of a TiCL, solution at 15% were weighed and titanium was precipitated by addition of [50 cc of ammonium hydroxide at 3271 and 10 cc of hydrogen peroxide at 35%.

The precipitate was filtered and thrice washed with 100 cc of ammoniacal water l/? of NH;,).

Separately 10 g of telluric acid (H,,TeO ,l were dissolved in 10 cc of water. 1.9 grams of ammonium paramolybdate and 0.3 grams of phosphoric acid at 85% were added thereto.

The resulting solution was joined to the precipitate before prepared and homogenized by stirring.

The whole was dried b heating and then calcined for 2 hours at 520C in a stream of air in a muffle.

The fraction having a graiiulometry in the range of from 45 to I50 mesh ASIM was collected and 6 cc of said fraction were put in a microreactor.

Propylene, ammonia, air and water at the molar ratios of 1/].3/12/10 were fed at the test conditions referred to in the table. wherein there are reported also the obtained results.

This example shows how catalytic compositions without titanium give remarkable lower results as to selec- Reaction CITY CHI, space Propylene Sclectii'it to llVll) KO ZiCl'ylOl'llUllt-B. lmi'mm l with? fg hrl'fi' f The introduction of the silica carrier is due to the fact that the catalytic composition is not in the solid state 5U at the reaction temperature and a vitrous mass forms i 25 U 2 47 I H H H which clogs the reactor.

EXAMPLE 7 EXAMPLE 5 A catalyst was prepared according to the procedure described in exam le 6. The same uantities of rea- A catalyst was prepared according to the procedure n r t d )l ud described in example 4. However use was made of 490 3 z jj i g s sf OX use z s c r grains of a IiCl solution at l5/r, of 300 cc ot ammol hx I M f I th nium hydroxide at 32' and of l(] cc of 12() volumes hyis l p zgx j xgl 3 5 li f g g gf lzg e Z drogcii peroxide. All other quantities of reagents were re Ortcd in the fnnowing hble Wcrep Oh the same. In the reaction of ammoxidation ot propylene mined p t. i '3 L i cticctcd at the experimental conditions reported in the table and with a feed molar ratio among propylene, air and water equal to l/LS/l 1/10. the results reported in y h I N v ht i 1 Reaction H space H comersion Selectivity t L e U1 temperature velocity lh") (moles '71) to A('N (Cl lnioles '1') 3O 46ml) 5h 53 I Q Reaction Propylene space (;H ;C(ll1\Cl'\lllll Selecthity 475 M] i lcnipcratiirc iclocit (moles ii to A('N l (i inioles "5| 4 m H 7 This example shows. as the preceding one. that the s i i c 15 97 77 performances of the catalyst are connected to the pres ence of titanium.

lts substitution with aluminium oxide causes a drastic selectivity lowering.

EXAMPLE 6 4() EXAMPLE 8 38 grams oftelluric acid were dissolved in 150 cc of Th catalysts re ared according to examples 2. 4 water and were joined to a solution prepared starting and 7 w re used in the reaction of oxidation of propytrom 3 grams ofammoniuni paramolyhdatc. 4 grams of l m l i 6 CC f Catalyst were put i a i. phosphoric acid in solution at 8571 and cc of water. crorcactor.

The resulting solution was poured in 200 cc of silica 45 The temperature was raised to the desired value by sol LudoxA.S. having 30% of SK): content. sending only air through the reactor at a space velocity The whole was dried by heating under stirring and of 600 cc per cc of catalyst per hour. Afterwards also subsequently was calcined in a muffle at 520C for 3 propylene and steam were fed. hours in a stream of air. Reaction conditions and obtained results are synthet- 6 cc ofcatalvst havin Y a ranulometrv in the ran e of Sl icall listed in the table.

. b E d g 3 (atalyst H /air/water Reaction Propylene C;,H, conversion Selectivity molar ratios temperature space (moles 71 i to Acrolein velocity (moles Z As in example I l/lZ/7 45!) 5t) 73 XI As in example 4 l/lZ/K 445 5t) 8" 9S |/|3.5/i 465 51) 9: s5 As in eutniplc 7 l/l3/7 45a 25 63 7o ironi 45 to 150 mesh were withdrawn and introduced into a niicroreactor whereto propylene. ammonia. air llltl water were led at molar ratios equal to At the aforesaid nperinicntal conditions We ohtaiiicd the results listed in the table EXAMPLES 9 to 18 32 grams of telluric acid (H TcO J were dissolved in 150 cc of water and 2.3 grams of phosphoric acid in solution at were added thereto. Separately 2 grams oi ammonium paramolyhdate were dissolved in 30 cc oiwater.

A third solution was prepared by dissolving in 100 cc of water in the case of example 9 2.4 g of silver nitrate in the case of example l 4.2g of zinc nitrate, in the case of example ll 3.8 g of cadmium acetate, in the the reaction is carried out at a temperature in the range of from 400C to 500C.

4. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that ca e of exam le 12 5,3 g of l i i inm i h 5 the reaction is carried out by feeding propylene, air and case of example 13 6.1 g of cerium nitrate, in the case ammonia with d p pyl n ir ati in the range of of example 14 6 g of zirconium nitrate, in the case of from 1:5 to 1:15 and the propylenelammfinia ratio example 5 g of a solution at 50% of manganese ning in th ang f frOm l1l.5 to 1:0.9. trate, in the case of example 16 5.6 g of iron nitrate, in 5. A process for the ammoxidation of propylene t the case of example 17 4.1 g of cobalt nitrate, in the g acrylonitrile according to claim 1 characterized in that case of example l8 4.l g of nickel nit the reaction is carried out in the presence of steam at The three solutions were joined and 50 g of titanium a molar ratio of steam to propylene offrom :1 to 2:1. dioxide were added. The whole was dried by heating 6. A process for the ammoxidation of propylene to under continuous tirrin The obt i d product w acrylonitrile according to claim 1 characterized in that calcined at 500C i air for 4 h ur i a muffl Th 15 the reaction is carried out at a pressure in the range of mass was ground and the fraction with a granulometry from atmospheric pressure to S atmospheres. in the range of from 45 to 150 mesh ASTM was tested A proce f r th flmmoxidation of propylene to in the ammoxidation reaction of propylene. by working acrylonitrile which comprises passing propylene, air as reported in example 1. and steam over a catalyst which consists essentially of The results are listed in the following table. 2 TeTi,,Mo,,P,,X,,,O,., said catalyst being the reaction EXAM- Elements Propylene space Reaction C=,H conversion Selectivity PLE constituting velocity (h) temperature (moles it to ACN the catalyst (C) (moles 7v) 9 Ag-Te'Ti-Mo-P-O 50 467 92.2 77.4 In Zn-Te-Ti-Mo-P-O 460 91.5 ass l Cd-TeTi-Mo-P-O 50 47a 89.8 78.l l2 Al-Te-Ti-Mo-P-O so 465 95 5 78.4 l 3 ceTeTi-Mo-P-o 50 46a 96 7s 14 Zr-Te-TiMo- P-O 50 47a 84 s 3. 2 l5 Mn-Te-Ti-Mo-P-O 40 465 89.4 so 16 Fe-Te Ti-Mo-P O 25 465 94 7s 17 Co-Te-TLMo-P'O 25 475 94.7 78.3 18 Ni-Te-Ti-Mo-P-O 25 465 7| .4 81.4

What we claim are: rodu t of;

l. A process for the ammoxidation of propylene to acrylonitrile characterized in that the reaction is carried out in the presence of a catalyst TeTi,,Mo,,P,,X,,,O,, which consists essentially of the reaction product of( l a member selected from the group consisting of telluric acid, metallic tellurium, and telluric oxide; (2) a member selected from the group consisting of titanium dioxide, titanium trichloride and titanium tetrachloride; (3) a member selected from the group consisting of ammonium molybdatc and ammonium paramolybdate; (4) phosphoric acid; and (5) wherein X is a member selected from the group consisting of the nitrates, acetates, carbonates and bicarbonates of silver, zinc, cad mium, aluminum, cerium, lanthanum, zirconium, manganese, iron, cobalt and nickel and m is between 0 and 0.3, n is between I and I5. p is between 005 and 0.4, q is between 0 and 0.3 and r has the value necessary for satisfying the valence with which the various elements are present in the formula, with the proviso that when q or m or q and m are zero the corresponding phosphoric acid or X member or phosphoric acid and X member, respectively, are omitted, said reaction product being obtained by first admixing the components in water and thereafter drying the mixture to obtain the reaction product.

2. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out at a temperature in the range of from 350C to 550C 3. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that l. a member selected from the group consisting of telluric acid, metallic tellurium and telluric oxide;

2. a member selected from the group consisting of titanium dioxide, titanium trichloride and titanium tetrachloride;

3. a member selected from the group consisting of ammonium molybdate and ammonium paramolybdate;

4, phosphoric acid,

5. wherein X is a member selected from the nitrates, acetates, carbonates and bicarbonates of silver, zinc, cadmium, aluminum, cerium, lanthanum, zirconium, manganese, iron, cobalt and nickel and m is between 0 and 0.3, n is between I and 15,17 is between 005 and 0.4, q is between 0 and 0.3 and r has the value necessary for satisfying the valence with which the various elements are present in the formula, said process being carried out at a temperature of from 350C to 550C and at a pressure from atmospheric to 5 atmospheres, the propylene to air ratio being in the range of 1:5 to l: [5. the propylene to ammonia ratio being l:l,5 to l:0.9 and thc propylene to steam ratio is from 20:1 to 2: l with the proviso that when q or m or q and m are zero the corresponding phosphoric acid or X member or phosphoric acid and X member, respectively, are omitted, said reaction product bcing obtained by first admixing the components in water and thereafter drying the mixturc to obtain the reaction product.

a r a x 

1. A PROCESS FOR THE AMMOXIDATION OF PROPYLENE TO ACRYLONITRILE CHARACTERIZED IN THAT THE REACTION IS CARRIER OUT IN THE PRESENCE OF A CATALYST TETINMOPQXMON WHICH CONSIST ESSENTIALLY OF THE REACTION PRODUCT OF (1) A MEMBER SELECTED FROM THE GROUP CONSISTING OF TELLURIC, METALLIC TALLURIUM, AND TELLURIC OXIDE, (2) A MEMBER SELECTED FROM THE GROUP CONSISTING OF TITANIUM DIOXIDE, TITANIUM AND TRICHLORIDE AND TITANIUM TETRACHLORIDE, (3) A MEMBER SELECTED FROM THE GROUP CONSISTING OF AMMONIUM MOLYBDATE AND AMMONIUM PARAMOLUBDATE, (4) PHOSPHORIC ACID, AND (5) WHEREIN X IA A MEMBER SELECTED FROM THE GROUP CONSISTING OF THE NITRATES, ACETATES, CARBONATES AND BICARBONATES OF SILVER, ZINC, CADIUM, ALUMINUM, CERIUM, LANTHANUM ZIRCONIUM, MANGANESE, IRON, COBALT, AND NICKEL AND M IS BETWEEN 0 AND 0.3, N IS BETWEEN 1 AND 15, P IS BETWEEN 0.05 AND 0.4, Q IS BETWEEN 0 AND 0.3 AND R HAS THE VALUE NECESSARY FOR SATISFYING THE VALENCE WITH WHICH THE VARIOUS ELEMENTS ARE PRESENT IN THE FORMULA, WITH THE PROVISO THAT WHEN Q OR M OR Q AND M ARE ZERO THE CORRESPONDING PHOSPHORIC ACID OR X MEMBER OR PHOSPHORIC ACID AND X MEMBER, RESPECTIVELY, ARE OMITTED, SAID REACTION PRODUCT BEING OBTAINED BY FIRST ADMIXING THE COMPONENTS IN WATER AND THEREAFTER DRYING THE MIXTURE TO OBTAIN THE REACTION PRODUCT.
 2. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out at a temperature in the range of from 350*C to 550*C.
 2. a member selected from the group consisting of titanium dioxide, titanium trichloride and titanium tetrachloride;
 3. a member selected from the group consisting of ammonium molybdate and ammonium paramolybdate;
 3. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out at a temperature in the range of from 400*C to 500*C.
 4. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out by feeding propylene, air and ammonia with a propylene/air ratio in the range of from 1:5 to 1:15 and the propylene/ammonia ratio being in the range of from 1:1.5 to 1: 0.9.
 4. phosphoric acid;
 5. wherein X is a member selected from the nitrates, acetates, carbonates and bicarbonates of silver, zinc, cadmium, aluminum, cerium, lanthanum, zirconium, manganese, iron, cobalt and nickel and m is between 0 and 0.3, n is between 1 and 15, p is between 0.05 and 0.4, q is between 0 and 0.3 and r has the value necessary for satisfying the valence with which the various elements are present in the formula, said process being carried out at a temperature of from 350*C to 550*C and at a pressure from atmospheric to 5 atmospheres, the propylene to air ratio being in the range of 1:5 to 1:15, the propylene to ammonia ratio being 1:1.5 to 1:0.9 and the propylene to steam ratio is from 20:1 to 2:1, with the proviso that when q or m or q and m are zero the corresponding phosphoric acid or X member or phosphoric acid and X member, respectively, are omitted, said reaction product being obtained by first admixing the components in water and thereafter drying the mixture to obtain the reaction product.
 5. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out in the presence of steam at a molar ratio of steam to propylene of from 20:1 to 2:1.
 6. A process for the ammoxidation of propylene to acrylonitrile according to claim 1 characterized in that the reaction is carried out at a pressure in the range of from atmospheric pressure to 5 atmospheres.
 7. A process for the ammoxidation of propylene to acrylonitrile which comprises passing propylene, air and steam over a catalyst which consists essentially of TeTinMopPqXmOr, said catalyst being the reaction product of: 